The invention relates to fluid-operated clutch release mechanisms, and more particularly to improvements in hydraulic mechanisms which can be utilized with advantage to release clutches, such as friction clutches, in the power trains of motor vehicles. Still more particularly, the invention relates to improvements in hydraulic clutch release mechanisms of the type wherein a cylinder-piston unit employs a cylindrical housing and an internal guide which defines with the housing an annular plenum chamber for a reciprocable piston adapted to actuate the clutch by way of a release bearing or the like.
A hydraulic clutch release mechanism which is disclosed in published German patent application Serial No. 196 35 101 A1 employs a piston which is arranged to change the condition of a diaphragm spring in a friction clutch of the character often employed in the power trains of motor vehicles. The piston of the release mechanism carries a lip seal which is secured thereto by a connector. The latter is anchored in or recessed into the lip seal, and an axially extending leg of such connector is recessed into the peripheral surface of the piston.
A drawback of the just described conventional clutch release mechanism is that the seal is apt to jam and/or to be tilted in the plenum chamber; this exerts an adverse influence upon the guidance of the piston and can affect the ability of the piston to actuate the clutch.